Acquired non-inflammatory myopathy

Acquired Non-Inflammatory Myopathy
Specialty	Neurology, Rheumatology
Symptoms	Muscle weakness, fatigue
Complications	Difficulty in performing daily activities
Causes	Various, including endocrine disorders, toxic myopathy, metabolic myopathy
Diagnostic method	Clinical evaluation, muscle biopsy, electromyography
Treatment	Address underlying cause, physical therapy
Prognosis	Varies depending on cause

Acquired non-inflammatory myopathy refers to a group of muscle diseases characterized by muscle weakness and dysfunction without significant inflammation. Unlike inflammatory myopathies, these conditions do not involve an immune-mediated attack on muscle tissue. Instead, they arise from a variety of other causes, including metabolic, toxic, and endocrine factors.

Causes

Acquired non-inflammatory myopathies can be caused by several factors:

• Endocrine disorders: Conditions such as hypothyroidism and Cushing's syndrome can lead to muscle weakness.
• Toxic myopathy: Exposure to certain drugs or toxins, such as statins or alcohol, can damage muscle tissue.
• Metabolic myopathy: Disorders of metabolism, such as mitochondrial myopathy, can impair muscle function.
• Nutritional deficiencies: Lack of essential nutrients, such as vitamin D, can lead to muscle weakness.

Symptoms

The primary symptom of acquired non-inflammatory myopathy is muscle weakness, which may be accompanied by fatigue and difficulty performing daily activities. The weakness is often symmetrical and affects proximal muscles, such as those in the shoulders and hips.

Diagnosis

Diagnosis of acquired non-inflammatory myopathy involves a combination of clinical evaluation and diagnostic tests:

• Clinical evaluation: A thorough medical history and physical examination are essential.
• Laboratory tests: Blood tests may reveal elevated levels of muscle enzymes, such as creatine kinase.
• Electromyography (EMG): This test assesses the electrical activity of muscles and can help differentiate between myopathic and neuropathic conditions.
• Muscle biopsy: A biopsy can provide definitive evidence of muscle pathology and help rule out inflammatory causes.

Treatment

Treatment of acquired non-inflammatory myopathy focuses on addressing the underlying cause:

• Endocrine disorders: Hormone replacement or regulation can improve muscle function.
• Toxic myopathy: Discontinuation of the offending drug or toxin is crucial.
• Metabolic myopathy: Dietary modifications and supplements may be beneficial.
• Physical therapy: Exercise and rehabilitation can help maintain muscle strength and function.

Prognosis

The prognosis for individuals with acquired non-inflammatory myopathy varies depending on the underlying cause and the effectiveness of treatment. Early diagnosis and management are key to improving outcomes.

Also see

• Inflammatory myopathy
• Muscular dystrophy
• Myopathy
• Neuromuscular disease